Vanillin

• CAS No.: 137-08-6
• Color: White
• Appearance: Powder
• Transport Package: Paper
• Specification: large
• Trademark: china
• Model NO.: E1422
• Origin: China
• HS Code: 2930400000
• Production Capacity: 5000kg/Year

Product Description

Vanillin (vanillin), also known as vanillin, is one of the most important biomass spices in modern society, which is widely used in cosmetics, tobacco, polymer synthesis, food additives and other industries. At present, there are some mature process methods to achieve artificial synthesis of vanillin, mainly including the following three: 1. [] lignin method, 2. [] guaiac phenol-formaldehyde method, 3. [] guaiol-acetic acid method. However, the above synthesis methods generally have some important defects. For example, the reaction needs to add strong alkali or toxic reagent as additives to produce a large amount of industrial wastewater; the oxidation degree is difficult to control, vanillin yield is low, the later separation and purification process is complex; the reaction conditions are harsh, the energy consumption is high, and the product cost is high. In the face of the increasingly severe energy and environmental crisis, the green, efficient and sustainable synthesis of vanillin has great economic value and practical prospects. Around the above problems, Fang Wenhao's research group of School of Chemical Science and Engineering, Yunnan University developed a Au / ZnO catalyst with Au 0 as the active center, which realized theas the solvent and O2 as the oxidant, and efficiently selected the catalytic oxidation of vanyl alcohol to synthesize vanillin without adding alkali. In the preparation of catalyst, Au 3 +, Zn 2 + ions (2-nm particles, small particles with average particle size of 2.2 ± 0.1 nm) Au catalyst. This method avoids the disadvantages of introducing more reagents, complex steps and difficult to control particle size distribution, and uses the strong interaction of Zn 2 + 2-methimidazole bridge coordination in porous ZIF-8 crystal so that it can be derived into a regular square ZnO nanosheet after 500ºC roasting. At the same time, the rigid cage structure and micropore structure in the catalyst precursor ZIF-8 can effectively limit the agglomeration of the gold precursor in the roasting process, thus generating small Au nanoparticles with uniform particle size in situ on ZnO. Through XPS, O2-TPD, DRIFT and other characterization, the catalyst surface electron-deficient Au 0 active site and abundant surface oxygen species, which revealed the excellent structure-activity relationship of the excellent performance of the catalyst: namely the adsorption and activation of alcohol hydroxyl group and O2. Finally, in the green synthesis of the high-added value chemical, the Au / ZnO catalyst oxidized vanillin alcohol in a yield of 100%, a TON value of 335 and an initial reaction rate of 124.2 mol mol-1 h-1. Compared with the currently reported single-metal catalyst system, the Au / ZnO catalyst shows the highest catalytic efficiency, and the catalyst shows excellent stability in continuous cycle reactions.